Acid Test for Marine Life

In Rio de Janeiro this week, environmental leaders from many nations are addressing one of our planet’s most serious yet still vastly under-recognized challenges: ocean acidification.

Ocean acidification, a process in which seawater chemistry changes when the ocean absorbs rising levels of atmospheric carbon dioxide, is profoundly affecting global waters and their ecologically and economically vital marine life. It is literally causing a sea change and threatening the fundamental chemical balance of ocean and coastal waters from pole to pole.

Because the consequences can be destructive to so many species, acidification is dubbed the “osteoporosis of the sea.” To build essential skeletons and shells, many marine plants and animals require calcium carbonate, an important mineral in seawater. But ocean acidification, if it continues unabated, could eventually inhibit the ability of oysters, clams, corals and other marine life to make hard protective shells and skeletons. In polar and other waters, the corrosive effect may also dissolve shells and skeletons already built.

Invisible to most, our fragile, indispensable marine life is increasingly facing the challenge of more corrosive waters as more CO2 is taken up by the ocean. Some creatures may benefit from rising acidity, but scientific evidence suggests that many, including corals, will not.

Corals provide the fundamental structure of our planet’s treasured coral reef ecosystem, and calcium carbonate is indispensable to making their skeletal framework. Increasing acidity means corals must use more energy to build their protective habitat. With too much ocean acidification, reefs will degrade and, ultimately, may disappear.

Coral reef systems provide the prime home for about 25 percent of all fish species. Developing nations with coastal economies and small island states are particularly vulnerable because they rely heavily on protein from the sea. Small island states depend on coral reefs for other basic needs as well as tourism revenues.

Already there are disturbing signs of ocean acidification’s corrosive effects. The Great Barrier Reef, for example, appears to be affected. In part, scientists attribute sluggish coral growth to escalating ocean acidification. In Alaska and New England, where colder waters hold more carbon dioxide, research is underway to examine the anticipated impact on king crab, clams, sea scallops and other economically important fisheries. Off British shores, scientists are testing the vulnerability of cold-water coral reefs that provide important protective habitat for young fish and other marine life. British and American scientists are also exploring impacts in the Arctic.

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We have made some advances. In the U.S. Pacific Northwest, oyster hatcheries began experiencing massive failures in 2005, threatening the $111 million West Coast shellfish industry, which supports more than 3,000 jobs. Once it became clear that corrosive water from the deeper ocean was upwelling onto the coastal shelf, water quality monitoring enabled shellfish farmers to know when to turn off inflowing seawater to protect young oysters. While such interventions are possible for laboratory operations, limiting the impact on wild fisheries is a much greater challenge.

With ocean acidification as an emerging global threat, Britain and the United States are joining a community of concerned nations to establish an Ocean Acidification International Coordination Center. The International Atomic Energy Agency will open the new center this summer at its Environmental Laboratories in Monaco.

Recognizing that ocean acidification knows no geographic boundaries, this pioneering center offers a valuable platform through which the international scientific community can come together around a single table.

This effort represents a major step forward, underscoring shared urgency to not just understand what changing ocean chemistry means for lives, livelihoods and communities but to get out ahead and manage the considerable global risks it poses.

John Beddington is chief scientific adviser to Prime Minister David Cameron. Jane Lubchenco is undersecretary of commerce for oceans and atmosphere, and administrator, U.S. National Oceanic and Atmospheric Administration.

A version of this op-ed appears in print on June 19, 2012, in The International Herald Tribune. Today's Paper|Subscribe